Echogenic enhancement for a needle

Abstract

A needle includes a surface with a plurality of first ultrasound reflecting depressions formed therein. The first depressions are distributed along at least a portion of a length of the needle separated from one another by intervening sections. Each of the first depressions is extending along a curve between first and second ends adjacent to corresponding ones of the intervening sections with troughs at which surfaces of each of the first depressions most closely approach a longitudinal axis of the needle being offset toward the first ends of each of the first depressions.

What is claimed is: 
     
       1. A needle, comprising:
 a longitudinal body extending between a proximal end and a distal end and including a lumen extending therethrough, an outer surface of the body including a plurality of first ultrasound reflecting depressions distributed along at least a portion of a length of the body separated from one another by intervening sections, each of the first depressions extending along a longitudinal axis of the needle from a first end to a second end and including a steep slope portion oriented to reflect ultrasound waves to a first transducer, a shallow slope portion oriented to reflect ultrasound waves back to a second transducer, and a trough including a gradual transition between the steep and shallow slope portions, the trough including an inner surface oriented to reflect ultrasound waves back to a third transducer positioned at an angle between the first and second transducers. 
 
     
     
       2. The needle of  claim 1 , wherein the steep slope portion of each of the first depressions is at the first end. 
     
     
       3. The needle of  claim 1 , wherein the shallow slope portion of the each of the first depressions is at the second end. 
     
     
       4. The needle of  claim 1 , wherein at each of the first ends, the steep slope gradually transitions to extend substantially perpendicular to the longitudinal axis of the needle. 
     
     
       5. The needle of  claim 1 , further comprising a tip located at the distal end of the needle, the tip being formed angled relative to the longitudinal axis of the needle and adapted to receive therein bodily tissue penetrated by the needle. 
     
     
       6. The needle of  claim 1 , wherein each of the first depressions extends around an entire circumference of the needle. 
     
     
       7. The needle of  claim 1 , wherein each of the first depressions extends around only a portion of a circumference of the needle. 
     
     
       8. The needle of  claim 1 , wherein the first end of each of the first depressions is at a distal end thereof. 
     
     
       9. The needle of  claim 1 , further comprising a plurality of second ultrasound reflecting depressions distributed along at least a further portion of the length of the needle separated from one another by the intervening sections, each of the second depressions extending along a curve between first and second ends adjacent to corresponding ones of the intervening sections with troughs at which surfaces of each of the second depressions most closely approach the longitudinal axis of the needle being offset toward the second ends of each of the second depressions. 
     
     
       10. The needle of  claim 9 , wherein the second end of each of the second depressions is at a proximal end thereof. 
     
     
       11. The needle of  claim 9 , wherein lengths of the intervening sections vary along the needle. 
     
     
       12. The needle of  claim 1 , wherein the intervening sections are substantially equal in length. 
     
     
       13. The needle of  claim 1 , further comprising a plurality of third ultrasound reflecting depressions distributed along at least a further portion of the length of the needle separated from one another by the intervening sections, each of the third depressions extending along a curve between first and second ends adjacent to corresponding ones of the intervening sections with troughs at which surfaces of each of the third depressions most closely approach the longitudinal axis of the needle being substantially centered between the first and second ends of each of the third depressions. 
     
     
       14. The needle of  claim 13 , wherein the first and third depression alternate along the length of the needle. 
     
     
       15. The needle of  claim 1 , wherein the body is formed of one of stainless steel and tungsten. 
     
     
       16. The needle of  claim 1 , further comprising a coating covering at least a portion of the needle, a material of the coating layer having an acoustic impedance selected to substantially match an acoustic impedance of bodily tissue within which the needle is to be used. 
     
     
       17. The needle of  claim 16 , wherein a speed of sound through the material of the coating layer is substantially less than that through the bodily tissue within which the needle is to be used. 
     
     
       18. A medical device, comprising:
 a longitudinal body extending between a proximal end and a distal end and including a lumen extending therethrough, an outer surface of the body including a plurality of first ultrasound reflecting depressions distributed along at least a portion of a length of the body separated from one another by intervening sections, each of the first depressions extending along a longitudinal axis of the device from a first end to a second end and including a steep slope portion oriented to reflect ultrasound waves to a first transducer, a shallow slope portion oriented to reflect ultrasound waves to a second transducer separated from the first transducer and a trough including a gradual transition between the steep and shallow slope portions, the trough including an inner surface oriented to reflect ultrasound waves to a third transducer positioned between the first and second transducers.